1. Field of the Invention
This invention relates to two-part multiple contact electrical connectors of the kind in which each part comprises a block of insulating material having multiple bores each housing a male or female pin. The `rear` end of each pin is connected, by soldering, crimping or similar method, to an insulated wire connector.
2. Description of Related Art
Certain classes of such connectors, used for example in military radar systems must be of a very high standard and must therefore be well sealed against the environment to prevent conductive fluids coming into contact with conductive parts of the connector and causing short circuiting. Adjacent bores in each block are therefore sealed from each other at the interface of the two connector parts. The rear faces of the blocks may be in an enclosed environment at non-atmospheric pressure or may be open to the atmosphere. In the former case a rear-end seal is preferably employed in each bore to relieve the pressure differential on the interface seal, and in the latter case a rear-end seal will tend to prevent short circuiting across the rear face. In the case of the exposed rear face the rear-end seal would of course be continuous with the insulation on the wire conductor. One system of seals is disclosed in U.K. Pat. No. 1406161 which uses three individual pressure sensitive seals for each contact pair--one at the rear end of each contact and one at the interface.
A single interface seal for the whole array of contacts is disclosed as prior art in the above patent specification. A flat sheet having a hole for each contact pair is disposed between the mating faces of the plug and socket connector parts. At the edge of each hole a step is formed in the sheet so that a square rim of thicker material surrounds each hole. This rim is designed to fit within the mating bores and closely against the contact when the connector is assembled, protruding a short distance into each of the bores. The sheet is in sealing contact with the flat mating faces across its entire surface between adjacent holes, but to maintain sufficient compression of the sheet to give an effective seal the connector parts must be clamped together under great pressure. In case of failure of this, because of insufficient clamping pressure for example, the bores are protected to some extent by the thickened rim around the hole. However this leads to a further problem that if this rim is to provide an effective seal it must be tightly compressed against the bore surfaces, that is, the contact must be a tight fit through the hole. On assembly, therefore, the rims of the holes are liable to damage by insertion of the contacts, and the contacts--generally thin pins requiring precise alignment for a good electrical connection in their respective sockets--may themselves be liable to be bent.